They edged in, struck dumb. Mitzi had guessed the reactor must be large, but large felt like such an insipid word compared to the fixture she faced. She stood on the lip of an immense hole; only a waist-high concrete barrier divided her from the drop. Steam rose from the hole, obscuring the opposite side, but Mitzi guessed it had to be at least a kilometre wide.

A little to her left, metal stairs rose sharply then opened onto a walkway that stretched across the divide. It looked hilariously fragile suspended above the abyss.

Mitzi swallowed as she approached the lip of the concrete divider and leaned forward, shining her torch into it. The beam reflected off something shiny, forty feet down. Mitzi squinted at it through the steam then felt her heart freeze as the thing inside the reactor moved.

“Eoin?” she asked, mouth dry, not daring to move. “You know about this station, right? What’s the fuel based on?”

“Its base?” he asked. “An altered form of poly-carbon-azatope.”

“I see. And that’s—”

“Water, of course.”

The movement in the reactor was increasing. Shiny black shapes rolled over each other, twisting and writhing, their moist skin glistening in the fuel.

“What’s wrong?” Nic asked.

Mitzi found it nearly impossible to say the words. “There’s a Cymic in the reactor.”

“Just one?”

“Yes.” The heaving shape rose, filling the entire width of the hole. “And also a million.”

Seeking somewhere quiet and dark, the million souls lost on Station 335 had congregated in the fuel-filled reaction chamber. And they’d consolidated. Central had never warned her about that.

Mitzi turned off her light, but it was too late. She’d already woken them.

CHAPTER FIFTY-FIVE

A thousand thoughts sped through her mind. With the Cymics diluting the fuel, would the charge still work? Would her team have time to get to the surface and be picked up? Was there even a sliver of a chance left of rescuing Adam and Ellen?

She had to try. She had to do her level best to complete the job, even if it cost her and her team—her beautiful, loyal team—their lives. Mitzi fumbled in the suit’s pouch for the detonator and whimpered.

“What’s wrong?” Skye’s voice was tense.

“The detonator’s gone.”

Mir swung towards her. “What? Did you drop it?”

“Impossible.” Mitzi’s mind ran through the previous hour and fixed on one single moment: when she’d been tracing wires in the maintenance room. Franc’s torch had wavered as though he’d moved.

He took it. Just in case I got away.

She thought of the four levels of stairs she needed to run down to fetch it, and a shudder ran down her back. She could no longer see the Cymics in the vat, but she could hear them, shifting and crawling upwards. She began backing towards the door, ushering her team behind her. The Cymic couldn’t hear in its current form, but that didn’t stop her from whispering. “You three get to the surface. Pick up Adam and Ellen if you can, but don’t take unnecessary risks. Get on the ship.”